Bladeshaft assemblies as may be used in construction equipment such as concrete cutting road saws are subject to extreme wear and adverse operating conditions. For instance, the amount of concrete dust and the necessary fluid slurry for keeping the dust down, generated when such a concrete cutting saw is used to cut into highway concrete, has an extremely negative effect on the life and operating characteristics of any component in the concrete cutting machine. Constant exposure to such dust and slurry can result in the need to service and replace components on a frequent basis that at times can be on the order of requiring service every eight hours. Of course, in the construction industry, it is highly undesirable to require servicing of the equipment on such a frequent basis since any such service requirement results in a stoppage of work and can delay a project. Accordingly, it would be desirable to provide a bladeshaft assembly for a concrete cutting saw that extended the amount of time between needed service actions.
An additional problem in the construction or concrete cutting business is an out of tolerance condition that may occur because of the high vibration experienced during the concrete cutting operation. For instance, if the relative displacement between the pulley on the drive shaft and the pulley on the bladeshaft change due to drift in positioning of one or the other of such pulleys as may be caused by vibration, excess wear will occur to the belt connecting the two pulleys as well as the actual cutting blade itself. Accordingly, it would be further advantageous if a bladeshaft assembly could be provided that would be less susceptible to drift in component placement as may be caused by the high-vibration characteristics of the concrete cutting environment.
Still another problem encountered in the concrete cutting environment is the susceptibility of the dust and slurry contamination entering the sealed area where the shaft bearings reside. Under such conditions, it may again be necessary to service the cutting machine on a more frequent basis than desired and as well, may result in the costly exercise of having to replace the entire blade shaft assembly if the servicing is not done when required. Servicing the bladeshaft assembly to repair or replace the shaft bearings is further complicated by the fact that the combination of the concrete dust and the slurry can create a hardened coating over the seal and attachment arrangement that protects the sealed bearing area. Given the problem of the difficulty in accessing the sealed bearing area due to concrete dust and slurry contamination, it would be advantageous if a sealing arrangement could be provided that would allow for substantially eliminating the contamination from entering the sealed bearing area and even more beneficial, in the unlikely event contamination did enter the bearing area, a simple and reliable attachment configuration would be provided to service the bearing area without the need to replace the entire bladeshaft assembly.
Yet another problem that has arisen in the manufacture and maintenance of concrete cutting machines is the time-consuming and unreliable method of positioning the pulleys on the respective drive and bladeshafts so as to be assured the alignment of such pulleys is substantially accurate. A typical pulley and shaft attachment arrangement involves a pulley have a center opening that is sized slightly larger than the diameter of the shaft on which it is to be mounted. The pulley is then secured to the shaft end by means of a number of setscrews that are tightened down onto the shaft. In the manufacturing process for performing this attachment, a worker must carefully assure that the displacement of the pulley on the shaft is accurate so that the pulley aligns appropriately with the counterpart pulley from the drive shaft. This process is time-consuming, is subject to assembly error and does not provide for consistent repeatable results for all concrete saw machines that are manufactured. The problem of alignment of the pulley onto the shaft during the initial manufacturing operation is also experienced in the field where it becomes necessary to replace a worn pulley. Additionally, because there is a difference in the diameter opening of the pulley and the diameter of the shaft, by securing the set screws onto the shaft, there is a tendency to render the shaft and pulley assembly as non-centric. In other words, the outer diameter of the pulley will not be concentric with the center longitudinal axis of the shaft. The effect of such non-centricity is that the cutting blade will be exposed to significantly more vibration and will not be as balanced as would be possible if the pulley and the blade shaft were concentric. Based on the problems associated with accurately and consistently aligning the pulley on the shaft, it would be advantageous if a better arrangement for attaching the pulley onto the shaft were developed, such better arrangement assuring that the results in both the manufacturing process and the service operation are accurate, repeatable and can be achieved in a simple and efficient manner.